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AIRCONDITIONING
b. Check the Amount of Refrigerant.
1. Check the sight glass on the receiver or the high
pressure pipe.
Important
Appropriate quantity:
There are no visible bubbles. But sometime
visible bubbles appear.
Excessive quantity:
There are no visible bubbles inside the flow. In
this case, however, the high and low pressures
will both be high, so the cooling will be
inadequate. Check the manifold gauge.
Insufficient refrigerant:
There are bubbles visible inside the flow.
(Bubbles are continuously flowing).
2. Check the amount of refrigerant by following the
instructions given in table below:
INSUFFI-
CIENT
APPROPRIATE
SIGHT GLASS
Fig. 48 - Sight glass indications (If fitted)
EXCESSIVE
Item Symptom
Amount of Refrigerant
Remedy
1.
Bubbles present in sight glass
Insufficient
Check for leak with gas leak detector
2.
No bubbles present in sight glass
Empty, proper or too much Refer to items 3 and 4
3.
No temperature difference between Empty or nearly empty
Evacuate and charge system. Then
compressor inlet and outlet
check for leak with gas leak detector.
4.
Temperature between compressor
Proper or too much
Refer to items 5 and 6
inlet and outlet is noticeably different
5.
Immediately after air conditioner
Too much
Discharge excessive refrigerant to
turned off, refrigerant in sight glass
specified amount.
stays clean.
6.
When air conditioner is turned off,
Empty, proper or too much Refer to items 3 and 4
refrigerant foams and then stays clear